The Accidental Solar House

I live in a solar house…sort of. Actually, I guess most houses are solar houses, as long as the sun is shining. It’s just the extent to which the sun helps the occupants stay comfortable that really makes the difference. But my house did pretty well by accident. I say “by accident” because I’m sure no one from the city planners to the developer to the builder ever considered this to be a solar house, or likely gave solar energy much of a thought whatsoever.

The back of our house faces south on a street that runs east to west, again, because it was probably the best direction for the topography or the efficient layout of the infrastructure, and not because anyone ever gave any thought to where the sun traveled across the sky. We get sun through our south windows when we most need it, and the two west windows are shaded by trees to block hot afternoon summer sun. The morning sun comes through our east patio door in the winter – just enough to warm the kitchen – and it gets blocked by the patio porch in the summer. The garage buffers the east side of the house. Of course, it’s not perfect. The front of the house faces north, and has slightly more window area than the south. Still, there are enough windows in the right places to make a difference. Room and window placement allow for natural ventilation. Coupled with a minimum of west-facing windows, this means we were able to remain comfortable without air conditioning, running our evaporative cooler infrequently during the summer.

The house is not perfect, but then whose is? This one is actually a long way from perfect, but it accidentally ended up with some good features that are hard to get when they aren’t built in at the beginning. The point is, with some planning around the unchangeable characteristics of the sun and wind, we could actually see entire subdivisions of intentional solar homes. There are plenty of precedents for this type of subdivision layout. What it takes is a commitment at the very early stages of development to help, rather than hinder, the process of building energy efficient homes. As an integral part of the larger issue of “green” development, this is fundamental.

Because folks tend to appreciate cutting to the chase, here are the bullet points:

  • Position the home to encourage solar heating and reduces the overheating potential of west-facing glass, even in Colorado.
  • Orient the width of the home on the lot within 30 degrees of south.
  • Keep the south glass area between 5-7% of the total finished floor. Too much south-facing glass will come back to haunt you, again, even in Colorado.
  • Provide a south roof area for future solar collector use.
  • Design the home for passive solar heating, reducing the size (and cost) of supplemental conventional heating.
  • Use a solar water heating system, thermal or electric (PV).
  • Once the electrical load is reduced through good design and construction, take advantage of solar electric (photovoltaic) systems to bring your home to “net-zero” energy use.

I should also mention here that good solar design is also good energy design. That is, the home should be designed as a complete package that includes all the elements of energy efficient home, like a good insulation and sealing package, sealed ductwork and high quality windows. The more attention put into an efficient shell, the more effective the solar impact.

Builders, no matter whether you build a solar home by accident or on purpose, your buyers will appreciate it, even if they don’t know it when they buy the house. There are benefits beyond the energy savings, like a bright morning kitchen, a glow that naturally lights the interior of the home, or a warm sitting room on a cold day. They may not ask for it, but they are likely to love it. I know I do, even if it was an accident.